On what data structure is a linked list implemented?

A linked list is implemented based on a data structure consisting of nodes, where each node contains two main elements:

1. Data (value).
2. A reference (pointer) to the next node in the list.

Unlike arrays, where elements are stored in a contiguous memory area, a linked list uses dynamic memory allocation, and each element is linked to the next via a pointer. This allows efficient insertion and deletion of elements without shifting the rest.

Example of a linked list node in Java:

class Node {
    int data;
    Node next;

    Node(int data) {
        this.data = data;
        this.next = null;
    }
}

Thus, a linked list is built on nodes with pointers, providing sequential access to elements.